WO2017145895A1

WO2017145895A1 - Refrigerator oil

Info

Publication number: WO2017145895A1
Application number: PCT/JP2017/005547
Authority: WO
Inventors: 洋平庄野; 亜喜良多田; 祐也水谷; 武大城戸; 英俊尾形
Original assignee: Ｊｘエネルギー株式会社
Priority date: 2016-02-24
Filing date: 2017-02-15
Publication date: 2017-08-31
Also published as: JPWO2017145895A1; CN108603133A; US10759982B2; JP6914908B2; CN108603133B; US20190078005A1

Abstract

The present invention provides a refrigerator oil: that contains, as a base oil, at least one type of oxygen-containing oil that has a carbon/oxygen mole ratio of 2.5-7.5; and that is to be used with a 1-chloro-2,3,3,3-tetrafluoropropene refrigerant.

Description

Refrigeration oil

The present invention relates to a refrigerator oil, an application of a composition containing at least one oxygen-containing oil as a base oil to a refrigerator oil, and a refrigerator oil having a composition containing at least one oxygen-containing oil as a base oil. Application for manufacturing.

Due to the problem of ozone layer destruction in recent years, CFC (chlorofluorocarbon) and HCFC (hydrochlorofluorocarbon), which have been used as refrigerants for refrigeration equipment, are subject to regulation, and HFC (hydrofluorocarbon) is used as a refrigerant instead. It is being done. However, among HFC refrigerants, HFC-134a, which is standardly used as a refrigerant for car air conditioners, has zero ozone depletion coefficient, but has a high global warming potential (GWP). ing.

Under such a background, there is an urgent need to develop a refrigerant that has little influence on the ozone layer and has a low GWP. For example, Patent Document 1 discloses the use of 1-chloro-2,3,3,3-tetrafluoropropene refrigerant from the standpoint of less impact on the ozone layer and less impact on global warming. .

By the way, when conventional CFC or HCFC is used as a refrigerant, refrigerating machine oil containing hydrocarbon oil such as mineral oil or alkylbenzene has been preferably used. However, refrigerating machine oil has a phase with a refrigerant depending on the type of refrigerant that coexists. Refrigerating machine oil needs to be developed for each refrigerant to exhibit unpredictable behavior such as solubility, lubricity, melt viscosity with refrigerant, thermal and chemical stability.

International Publication No. 2012/157773

An object of the present invention is to provide a refrigerating machine oil having excellent compatibility with a 1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd) refrigerant.

The present invention contains at least one oxygenated oil having a carbon / oxygen molar ratio of 2.5 or more and 7.5 or less as a base oil, and is a 1-chloro-2,3,3,3-tetrafluoropropene refrigerant. Refrigerating machine oil for use with the present invention is provided.

The present invention also relates to a refrigerating machine oil containing at least one oxygenated oil having a carbon / oxygen molar ratio of 2.5 or more and 7.5 or less as a base oil, 1-chloro-2,3,3,3 A working fluid composition for a refrigerator, comprising a tetrafluoropropene refrigerant.

The above refrigerating machine oil preferably contains, as an oxygen-containing oil, an ester of a fatty acid and a polyhydric alcohol in which the proportion of the fatty acid having 4 to 20 carbon atoms is 20 to 100 mol%.

The above refrigerating machine oil is an acid scavenger, antioxidant, extreme pressure agent, oiliness agent, antifoaming agent, metal deactivator, antiwear agent, viscosity index improver, pour point depressant, cleaning dispersant, friction You may further contain the at least 1 sort (s) of additive chosen from the group which consists of a regulator and a rust preventive agent.

The present invention also relates to a refrigerating machine oil or a working fluid composition for a refrigerating machine comprising a composition containing at least one oxygen-containing oil having a carbon / oxygen molar ratio of 2.5 or more and 7.5 or less as a base oil. In the application, the refrigeration oil is used together with a 1-chloro-2,3,3,3-tetrafluoropropene refrigerant, and the working fluid composition for the refrigeration is composed of the refrigeration oil and 1-chloro-2,3,3. , 3-Tetrafluoropropene refrigerant.

Further, the present invention provides a refrigerating machine oil or a working fluid composition for a refrigerating machine comprising a composition containing at least one oxygen-containing oil having a carbon / oxygen molar ratio of 2.5 or more and 7.5 or less as a base oil. The refrigeration oil is used together with 1-chloro-2,3,3,3-tetrafluoropropene refrigerant, and the working fluid composition for the refrigeration is composed of refrigeration oil and 1-chloro-2, It can also be said that it contains 3,3,3-tetrafluoropropene refrigerant.

According to the present invention, it is possible to provide refrigerating machine oil excellent in compatibility with 1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd) refrigerant.

Hereinafter, embodiments of the present invention will be described in detail.

The refrigerating machine oil according to the present embodiment contains at least one oxygen-containing oil having a carbon / oxygen molar ratio of 2.5 or more and 7.5 or less as a base oil, and 1-chloro-2,3,3,3 -Used with tetrafluoropropene refrigerant.

The working fluid composition for a refrigerator according to this embodiment includes a refrigerator oil containing at least one oxygenated oil having a carbon / oxygen molar ratio of 2.5 or more and 7.5 or less as a base oil, and 1-chloro. -2,3,3,3-tetrafluoropropene refrigerant. The working fluid composition for a refrigerator according to the present embodiment includes an embodiment containing the refrigerator oil according to the present embodiment and a 1-chloro-2,3,3,3-tetrafluoropropene refrigerant. Is done.

The base oil is at least one oxygen-containing oil having a carbon / oxygen molar ratio of 2.5 or more and 7.5 or less. The carbon / oxygen molar ratio of the oxygenated oil is preferably 3.2 or more, more preferably 3.5 or more, still more preferably 4.0 or more, particularly preferably from the viewpoint of compatibility with the refrigerant and stability. 4.3 or more, preferably 5.8 or less, more preferably 5.2 or less, and still more preferably 5.0 or less. The carbon / oxygen molar ratio can be quantitatively analyzed by a general elemental analysis method. Examples of the method for analyzing carbon include a method of analyzing by a thermal conductivity method or a gas chromatography method after conversion to carbon dioxide by combustion. As a method for analyzing oxygen, a carbon reduction method in which the oxygen is converted into carbon monoxide by carbon and then quantitatively analyzed is generally used, and the Shutze-Unteraucher method has been widely put into practical use.

The surface tension of the oxygen-containing oil is preferably 0.02 to 0.04 N / m, more preferably 0.025 to 0.035 N / m, and more preferably 0.025 to 0.035 N / m, from the viewpoint of efficiently circulating the refrigerating machine oil together with the refrigerant. Preferably it is about 0.03 N / m. The surface tension in the present invention means a value measured according to JIS K2241.

The oxygenated oil may be an ester, polyvinyl ether, polyalkylene glycol, carbonate, ketone, polyphenyl ether, silicone, polysiloxane, perfluoroether, etc., preferably an ester, polyvinyl ether or polyalkylene glycol, more preferably Ester.

Examples of esters include aromatic esters, dibasic acid esters, polyol esters, complex esters, carbonate esters, and mixtures thereof, and polyol esters are preferably used.

As the aromatic ester, an ester of an aromatic carboxylic acid having 1 to 6 valences, preferably 1 to 4 valences, more preferably 1 to 3 valents, and an aliphatic alcohol having 1 to 18 carbon atoms, preferably 1 to 12 carbon atoms. Etc. are used. Specific examples of the monovalent to hexavalent aromatic carboxylic acid include benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, and mixtures thereof. Specific examples of the aliphatic alcohol having 1 to 18 carbon atoms include methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, and penta. Examples include decanol, hexadecanol, heptadecanol, octadecanol, and mixtures thereof. These aliphatic alcohols having 1 to 18 carbon atoms may be linear or branched. The divalent or higher valent aromatic carboxylic acid may be a simple ester composed of an alcohol composed of one kind of aliphatic alcohol, or a complex ester composed of an alcohol composed of two or more kinds of aliphatic alcohol. May be.

Dibasic acid esters include dibasic acids having 5 to 10 carbon atoms such as glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, methanol, ethanol, propanol, butanol, pentanol, hexanol, Preferred are esters with monohydric alcohols having 1 to 15 carbon atoms having a linear or branched alkyl group such as heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, and the like, and mixtures thereof. Used.

Polyol ester is an ester synthesized from polyhydric alcohol and fatty acid. A saturated fatty acid is preferably used as the fatty acid. The number of carbon atoms of the fatty acid is preferably 4 to 20, more preferably 4 to 18, still more preferably 4 to 9, and particularly preferably 5 to 9. The polyol ester may be a partial ester in which some of the hydroxyl groups of the polyhydric alcohol are not esterified and remain as hydroxyl groups, or may be a complete ester in which all of the hydroxyl groups are esterified. It may be a mixture of an ester and a complete ester. The hydroxyl value of the polyol ester is preferably 10 mgKOH / g or less, more preferably 5 mgKOH / g or less, still more preferably 3 mgKOH / g or less.

The proportion of the fatty acid having 4 to 20 carbon atoms in the fatty acid constituting the polyol ester is preferably 20 to 100 mol%, more preferably 50 to 100 mol%, still more preferably 70 to 100 mol%, particularly preferably 90 to 100 mol%. Mol%.

Specific examples of the fatty acid having 4 to 20 carbon atoms include butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, and pentadecanoic acid. Hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid and icosanoic acid. These fatty acids having 4 to 20 carbon atoms may be linear or branched. The fatty acid having 4 to 20 carbon atoms is preferably a fatty acid having a branch at the α-position and / or β-position, and more preferably 2-methylpropanoic acid, 2-methylbutanoic acid, 2-methylpentanoic acid, 2-methyl Hexanoic acid, 2-ethylpentanoic acid, 2-methylheptanoic acid, 2-ethylhexanoic acid, 3,5,5-trimethylhexanoic acid, 2-ethylhexadecanoic acid and the like, more preferably 2-ethylhexanoic acid or 3 5,5-trimethylhexanoic acid.

The fatty acid may contain a fatty acid other than a fatty acid having 4 to 20 carbon atoms. Examples of fatty acids other than fatty acids having 4 to 20 carbon atoms include, for example, fatty acids having 21 to 24 carbon atoms. Specific examples include linear or branched henicoic acid, linear or branched docosanoic acid, Examples thereof include linear or branched tricosanoic acid and linear or branched tetracosanoic acid.

As the polyhydric alcohol constituting the polyol ester, a polyhydric alcohol having 2 to 6 hydroxyl groups is preferably used. The number of carbon atoms of the polyhydric alcohol is preferably 4 or more, more preferably 5 or more, and preferably 12 or less, more preferably 10 or less. Specifically, hindered alcohols such as neopentyl glycol, trimethylol ethane, trimethylol propane, trimethylol butane, di- (trimethylol propane), tri- (trimethylol propane), pentaerythritol, dipentaerythritol are preferable. . Since the polyhydric alcohol is particularly excellent in compatibility with the refrigerant and hydrolysis stability, pentaerythritol or a mixed alcohol of pentaerythritol and dipentaerythritol is more preferable.

The complex ester is an ester of at least two kinds of acids selected from monohydric fatty acids and dibasic acids and monohydric alcohols and / or polyhydric alcohols, or monohydric fatty acids and / or dibasic acids, and monovalents. An ester with at least two alcohols selected from alcohols and polyhydric alcohols. The complex ester may be an ester of a dibasic acid and at least two kinds of alcohols selected from monohydric alcohols and polyhydric alcohols. As fatty acids, dibasic acids, monohydric alcohols, and polyhydric alcohols, those exemplified in the description of dibasic acid esters and polyol esters can be used.

The carbonate ester is a compound having a carbonate ester structure represented by the following formula (A) in the molecule. The carbonate ester may have one carbonate ester structure or a plurality of carbonate ester structures in one molecule.

As the alcohol constituting the carbonate ester, the above-mentioned aliphatic alcohols and polyols can be used, and polyglycols and those obtained by adding polyglycols to polyols can also be used. The carbonate ester may be composed of carbonic acid and a fatty acid and / or dibasic acid.

Among the carbonate esters, carbonate esters having a structure represented by the following formula (A-1) are preferable.

[The formula (A-1) in, ^{X 1} is a hydrogen atom, an alkyl group, a cycloalkyl group or the following formula (A-2):
Y ^2- (OA ³ ) _e- (A-2)
(In the above formula (A-2), Y ² represents a hydrogen atom, an alkyl group or a cycloalkyl group, A ³ represents an alkylene group having 2 to 4 carbon atoms, and e represents an integer of 1 to 50) A ¹ and A ² may be the same or different and each represents an alkylene group having 2 to 4 carbon atoms; Y ¹ represents a hydrogen atom, an alkyl group or a cycloalkyl group; Represents a residue of a compound having 3 to 20 hydroxyl groups, a is an integer of 1 to 20, b is an integer of 0 to 19 and a + b = 3 to 20, c is an integer of 0 to 50, d is 1 Each represents an integer of ~ 50. ]

In the above formula (A-1), X ¹ represents a hydrogen atom, an alkyl group, a cycloalkyl group or a group represented by the above formula (A-2). The number of carbon atoms of the alkyl group is not particularly limited, but may be, for example, 1-24, preferably 1-18, more preferably 1-12. The alkyl group may be linear or branched.

Specific examples of the alkyl group having 1 to 24 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, straight Chain or branched pentyl group, linear or branched hexyl group, linear or branched heptyl group, linear or branched octyl group, linear or branched nonyl group, linear or branched decyl group, linear or Branched undecyl group, linear or branched dodecyl group, linear or branched tridecyl group, linear or branched tetradecyl group, linear or branched pentadecyl group, linear or branched hexadecyl group, linear or branched Heptadecyl group, linear or branched octadecyl group, linear or branched nonadecyl group, linear or branched icosyl group, linear or branched heicosyl group, linear or branched docosyl group, linear or branched tricosyl group , Linear or Such as branch tetracosyl group, and the like.

Specific examples of the cycloalkyl group include a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group.

In the above formula (A-2), the alkylene group having 2 to 4 carbon atoms represented by A ³ includes an ethylene group, a propylene group, a trimethylene group, a butylene group, a tetramethylene group, a 1-methyltrimethylene group, 2 -Methyltrimethylene group, 1,1-dimethylethylene group, 1,2-dimethylethylene group and the like are exemplified.

Y ² in the above formula (A-2) is a hydrogen atom, an alkyl group or a cycloalkylalkyl group. The number of carbon atoms of the alkyl group is not particularly limited, but may be, for example, 1-24, preferably 1-18, more preferably 1-12. The alkyl group may be linear or branched. Specific examples of the alkyl group having 1 to 24 carbon atoms include the groups listed in the description relating to X ¹ .

Y ² is preferably a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, more preferably a hydrogen atom, methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso- Butyl group, sec-butyl group, tert-butyl group, n-pentyl group, iso-pentyl group, neo-pentyl group, n-hexyl group, iso-hexyl group, n-heptyl group, iso-heptyl group, n- An octyl group, an iso-octyl group, an n-nonyl group, an iso-nonyl group, an n-decyl group, an iso-decyl group, an n-undecyl group, an iso-undecyl group, an n-dodecyl group or an iso-dodecyl group.

X ¹ is a hydrogen atom, preferably an alkyl group having 1 to 12 carbon atoms or a group represented by the formula (A-2), more preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, iso-pentyl group, neo-pentyl group, n-hexyl group, iso-hexyl group, n-heptyl group, iso-heptyl group, n-octyl group, iso-octyl group, n-nonyl group, iso-nonyl group, n-decyl group, iso-decyl group, n-undecyl group, iso-undecyl group, An n-dodecyl group, an iso-dodecyl group or a group represented by the formula (A-2).

Specific examples of the compound having 3 to 20 hydroxyl groups with B as a residue include the aforementioned polyols.

A ¹ and A ² may be the same or different, each represents an alkylene group having 2 to 4 carbon atoms. A ¹ and A ² are, for example, ethylene group, propylene group, trimethylene group, butylene group, tetramethylene group, 1-methyltrimethylene group, 2-methyltrimethylene group, 1,1-dimethylethylene group, 1, It may be a 2-dimethylethylene group.

Y ¹ is a hydrogen atom, an alkyl group or a cycloalkylalkyl group. The number of carbon atoms of the alkyl group is not particularly limited, but is, for example, 1 to 24, preferably 1 to 18, and more preferably 1 to 12. The alkyl group may be linear or branched. Specific examples of the alkyl group having 1 to 24 carbon atoms include the groups listed in the description relating to X ¹ .

Y ¹ is preferably a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, more preferably a hydrogen atom, methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso- Butyl group, sec-butyl group, tert-butyl group, n-pentyl group, iso-pentyl group, neo-pentyl group, n-hexyl group, iso-hexyl group, n-heptyl group, iso-heptyl group, n- An octyl group, an iso-octyl group, an n-nonyl group, an iso-nonyl group, an n-decyl group, an iso-decyl group, an n-undecyl group, an iso-undecyl group, an n-dodecyl group or an iso-dodecyl group.

In the above formulas (A-1) and (A-2), c, d and e each represent the degree of polymerization of the polyoxyalkylene moiety. These polyoxyalkylene moieties may be the same or different from each other in the molecule. When the carbonate ester has a plurality of different polyoxyalkylene moieties, the polymerization mode of the oxyalkylene group is not particularly limited, and may be random copolymerization or block copolymerization.

Polyvinyl ether has a structural unit represented by the following formula (1).

[Wherein R ¹ , R ² and R ³ may be the same or different from each other and each represents a hydrogen atom or a hydrocarbon group, and R ⁴ represents a divalent hydrocarbon group or a divalent ether-bonded oxygen-containing carbon atom. Represents a hydrogen group, R ⁵ represents a hydrocarbon group, and m represents an integer of 0 or more. When m is 2 or more, the plurality of R ⁴ may be the same as or different from each other. ]

The number of carbon atoms of the hydrocarbon group represented by R ¹ , R ² and R ³ in formula (1) is preferably 1 or more, more preferably 2 or more, still more preferably 3 or more, and preferably 8 or less. More preferably, it is 7 or less, More preferably, it is 6 or less. In Formula (1), at least one of R ¹ , R ² and R ³ is preferably a hydrogen atom, and more preferably all are hydrogen atoms.

The carbon number of the divalent hydrocarbon group and the ether bond oxygen-containing hydrocarbon group represented by R ⁴ in the formula (1) is preferably 1 or more, more preferably 2 or more, still more preferably 3 or more, Preferably it is 10 or less, More preferably, it is 8 or less, More preferably, it is 6 or less. The divalent ether bond oxygen-containing hydrocarbon group represented by R ⁴ in Formula (1) may be, for example, a hydrocarbon group having oxygen in the side chain to form an ether bond.

R ⁵ in the formula (1) is preferably a hydrocarbon group having 1 to 20 carbon atoms. Examples of the hydrocarbon group include an alkyl group, a cycloalkyl group, a phenyl group, an aryl group, and an arylalkyl group. The hydrocarbon group is preferably an alkyl group, more preferably an alkyl group having 1 to 5 carbon atoms.

M in the formula (1) is preferably 0 or more, more preferably 1 or more, still more preferably 2 or more, and is preferably 20 or less, more preferably 18 or less, and still more preferably 16 or less. The average value of m in all structural units constituting the polyvinyl ether is preferably 0 to 10.

The polyvinyl ether may be a homopolymer composed of one type selected from the structural unit represented by the formula (1), or composed of two or more types selected from the structural unit represented by the formula (1). The copolymer may be a copolymer composed of the structural unit represented by the formula (1) and another structural unit. When polyvinyl ether is a copolymer, lubricity, insulating properties, hygroscopicity, and the like can be further improved while satisfying compatibility with the refrigerant of the refrigerating machine oil. At this time, the various characteristics of the refrigerating machine oil can be made desired by appropriately selecting the kind of raw material monomer, the kind of initiator, the ratio of structural units in the copolymer, and the like. Therefore, it is possible to freely obtain refrigerating machine oil that meets different requirements such as lubricity and compatibility depending on the type of compressor, the material of the lubricating part, the refrigerating capacity, the type of refrigerant, etc. in the refrigeration system or air conditioning system. The copolymer may be either a block copolymer or a random copolymer.

When the polyvinyl ether is a copolymer, the copolymer is preferably a structural unit (1-1) represented by the above formula (1) and R ⁵ is an alkyl group having 1 to 3 carbon atoms; And a structural unit (1-2) represented by the above formula (1) and wherein R ⁵ is an alkyl group having 3 to 20, preferably 3 to 10, and more preferably 3 to 8 carbon atoms. R ⁵ in the structural unit (1-1) is preferably an ethyl group, and R ⁵ in the structural unit (1-2) is preferably an isobutyl group. When the polyvinyl ether is a copolymer having the structural units (1-1) and (1-2), the molar ratio of the structural unit (1-1) to the structural unit (1-2) is preferably 5:95 to 95: 5, more preferably 20:80 to 90:10, and still more preferably 70:30 to 90:10. When the molar ratio is within the above range, the compatibility with the refrigerant can be further improved, and the hygroscopicity tends to be lowered.

The polyvinyl ether may be composed only of the structural unit represented by the above formula (1), but may be a copolymer further having a structural unit represented by the following formula (2). . In this case, the copolymer may be a block copolymer or a random copolymer.

[Wherein R ⁶ to R ⁹ may be the same as or different from each other, and each represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. ]

Polyvinyl ether is obtained by polymerization of a vinyl ether monomer corresponding to formula (1), or a copolymer of a vinyl ether monomer corresponding to formula (1) and a hydrocarbon monomer having an olefinic double bond corresponding to formula (2). It can be produced by polymerization. The vinyl ether monomer corresponding to the structural unit represented by the formula (1) is preferably a monomer represented by the following formula (3).

^{^{^{Wherein, R 1, R 2, R}}} 3, R 4, R 5 and m ^{^{^{is, R 1, R 2, R}}} 3, R 4, R 5 and the same definition and m, respectively formula (1) Indicates. ]

The polyvinyl ether preferably has the following terminal structure (A) or (B).

(A) A structure in which one end is represented by formula (4) or (5) and the other end is represented by formula (6) or (7).

[Wherein R ¹¹ , R ²¹ and R ³¹ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, and R ⁴¹ is a divalent divalent hydrocarbon having 1 to 10 carbon atoms. A hydrocarbon group or a divalent ether-bonded oxygen-containing hydrocarbon group, R ⁵¹ represents a hydrocarbon group having 1 to 20 carbon atoms, and m represents the same definition as m in formula (1). When m is 2 or more, the plurality of R ⁴¹ may be the same as or different from each other. ]

[Wherein, R ⁶¹ , R ⁷¹ , R ⁸¹ and R ⁹¹ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. ]

[Wherein R ¹² , R ²² and R ³² may be the same as or different from each other, each represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, and R ⁴² is a divalent divalent hydrocarbon having 1 to 10 carbon atoms. R represents a hydrocarbon group or a divalent ether-bonded oxygen-containing hydrocarbon group, R ⁵² represents a hydrocarbon group having 1 to 20 carbon atoms, and m represents the same definition as m in formula (1). When m is 2 or more, the plurality of R ⁴¹ may be the same or different. ]

[Wherein R ⁶² , R ⁷² , R ⁸² and R ⁹² may be the same or different from each other, and each represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. ]

(B) A structure in which one end is represented by the above formula (4) or (5) and the other end is represented by the following formula (8).

[Wherein R ¹³ , R ²³ and R ³³ may be the same or different from each other, and each represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms. ]

Among such polyvinyl ethers, the following polyvinyl ethers (a), (b), (c), (d) and (e) are particularly preferably used as the main component (base oil) of the refrigerating machine oil.
(A) one end is represented by formula (4) or (5) and the other end is represented by formula (6) or (7), and R ¹ and R in formula (1) Polyvinyl ether in which ² and R ³ are both hydrogen atoms, m is an integer of 0 to 4, R ⁴ is a divalent hydrocarbon group having 2 to 4 carbon atoms, and R ⁵ is a hydrocarbon group having 1 to 20 carbon atoms .
(B) It has only the structural unit represented by Formula (1), Comprising: One terminal is represented by Formula (4), and the other terminal has a structure represented by Formula (6). In Formula (1), R ¹ , R ² and R ³ are all hydrogen atoms, m is an integer of 0 to 4, R ⁴ is a divalent hydrocarbon group having 2 to 4 carbon atoms, and R ⁵ is 1 carbon atom. Polyvinyl ether which is ˜20 hydrocarbon groups.
(C) One end is represented by formula (4) or (5) and the other end is represented by formula (8), and R ¹ , R ² and R ³ in formula (1) Are all hydrogen atoms, m is an integer of 0 to 4, R ⁴ is a divalent hydrocarbon group having 2 to 4 carbon atoms, and R ⁵ is a hydrocarbon group having 1 to 20 carbon atoms.
(D) It has only the structural unit represented by Formula (1), and has one end represented by Formula (5) and the other end represented by Formula (8). In Formula (1), R ¹ , R ² and R ³ are all hydrogen atoms, m is an integer of 0 to 4, R ⁴ is a divalent hydrocarbon group having 2 to 4 carbon atoms, and R ⁵ is 1 carbon atom. Polyvinyl ether which is ˜20 hydrocarbon groups.
(E) any one of the above (a), (b), (c) and (d), wherein R ⁵ in the formula (1) is a hydrocarbon group having 1 to 3 carbon atoms and the R And polyvinyl ether having a structural unit in which ⁵ is a hydrocarbon group having 3 to 20 carbon atoms.

The weight average molecular weight of polyvinyl ether is preferably 500 or more, more preferably 600 or more, preferably 3000 or less, more preferably 2000 or less, and further preferably 1500 or less. When the weight average molecular weight of polyvinyl ether is 500 or more, the lubricity in the presence of a refrigerant is excellent. When the weight average molecular weight is 3000 or less, the composition range showing compatibility with the refrigerant under a low temperature condition is widened, and poor lubrication of the refrigerant compressor and inhibition of heat exchange in the evaporator can be suppressed.

The number average molecular weight of the polyvinyl ether is preferably 500 or more, more preferably 600 or more, preferably 3000 or less, more preferably 2000 or less, and further preferably 1500 or less. When the number average molecular weight of polyvinyl ether is 500 or more, the lubricity in the presence of a refrigerant is excellent. When the number average molecular weight is 3000 or less, the composition range showing compatibility with the refrigerant under a low temperature condition is widened, and poor lubrication of the refrigerant compressor and inhibition of heat exchange in the evaporator can be suppressed.

The weight average molecular weight and number average molecular weight of polyvinyl ether mean the weight average molecular weight and the number average molecular weight (polystyrene (standard sample) conversion value) obtained by GPC analysis, respectively. A weight average molecular weight and a number average molecular weight can be measured as follows, for example.

Use chloroform as a solvent and prepare a solution with a sample concentration of 1% by mass by dilution. The sample solution is analyzed using a GPC apparatus (Waters Alliance 2695). The analysis is performed using a refractive index detector using a column having a solvent flow rate of 1 ml / min and an analyzable molecular weight of 100 to 10,000. The relationship between the column retention time and the molecular weight is determined using a polystyrene standard with a clear molecular weight, a calibration curve is separately prepared, and the molecular weight of the sample is determined from the obtained retention time.

In the production process of polyvinyl ether, side reactions may occur and unsaturated groups such as aryl groups may be formed in the molecule. However, the thermal stability of polyvinyl ether itself is improved, and sludge is generated due to the formation of a polymer. From the viewpoint of suppression and suppression of peroxide generation due to a decrease in antioxidant properties (antioxidation properties), the polyvinyl ether is preferably a polyvinyl ether having a low degree of unsaturation derived from an unsaturated group or the like. The degree of unsaturation of the polyvinyl ether is preferably 0.04 meq / g or less, more preferably 0.03 meq / g or less, still more preferably 0.02 meq / g or less. The peroxide value of polyvinyl ether is preferably 10.0 meq / kg or less, more preferably 5.0 meq / kg or less, and still more preferably 1.0 meq / kg. The carbonyl value of polyvinyl ether is preferably 100 ppm by weight or less, more preferably 50 ppm by weight or less, and still more preferably 20 ppm by weight or less. The hydroxyl value of polyvinyl ether is preferably 10 mgKOH / g or less, more preferably 5 mgKOH / g or less, and still more preferably 3 mgKOH / g or less.

In the present invention, the degree of unsaturation, the peroxide value, and the carbonyl value are values measured by a standard oil analysis test method established by the Japan Oil Chemists' Society. That is, the degree of unsaturation in the present invention is determined by reacting a sample with a Wis solution (ICl-acetic acid solution) and leaving it in the dark, then reducing excess ICl to iodine and titrating the iodine content with sodium thiosulfate. The iodine value is calculated, and the iodine value is converted to a vinyl equivalent (meq / g). The peroxide value in the present invention is a value (meq / kg) obtained by adding potassium iodide to a sample, titrating the resulting free iodine with sodium thiosulfate, and converting this free iodine to the number of milliequivalents per 1 kg of the sample. Say. The carbonyl value in the present invention is a calibration curve obtained by allowing 2,4-dinitrophenylhydrazine to act on a sample to produce a chromoid quinoid ion, measuring the absorbance of this sample at 480 nm, and using cinnamaldehyde as a standard substance in advance. The value (weight ppm) converted into the amount of carbonyl based on the above. The hydroxyl value in the present invention means a hydroxyl value measured according to JIS K0070: 1992.

The polyalkylene glycol may be polyethylene glycol, polypropylene glycol, polybutylene glycol, or the like. The structural unit of polyalkylene glycol is, for example, oxyethylene, oxypropylene or oxybutylene. Polyalkylene glycols having these structural units can be obtained by ring-opening polymerization using monomers ethylene oxide, propylene oxide, and butylene oxide as raw materials.

Examples of the polyalkylene glycol include a compound represented by the following formula (9).
R ^α -[(OR ^β ) _f -OR ^γ ] _g (9)
[In the formula (1), R ^α represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an acyl group having 2 to 10 carbon atoms, or a residue of a compound having 2 to 8 hydroxyl groups, and R ^β represents carbon R 2 represents an alkylene group having 2 to 4, R ^γ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an acyl group having 2 to 10 carbon atoms, f represents an integer of 1 to 80, and g represents 1 to Represents an integer of 8. ]

In the above formula (9), the alkyl group represented by R ^α and R ^γ may be linear, branched or cyclic. The number of carbon atoms of the alkyl group is preferably 1 to 10, more preferably 1 to 6. When the number of carbon atoms in the alkyl group exceeds 10, the compatibility with the refrigerant tends to decrease.

The alkyl group part of the acyl group represented by R ^α and R ^γ may be linear, branched or cyclic. The carbon number of the acyl group is preferably 2 to 10, more preferably 2 to 6. If the number of carbon atoms in the acyl group exceeds 10, the compatibility with the refrigerant may be reduced and phase separation may occur.

When the groups represented by R ^α and R ^γ are both alkyl groups or are both acyl groups, the groups represented by R ^α and R ^γ may be the same or different. When g is 2 or more, a plurality of groups represented by R ^α and R ^γ in the same molecule may be the same as or different from each other.

When the group represented by R ^α is a residue of a compound having 2 to 8 hydroxyl groups, this compound may be a chain or a ring.

In the polyalkylene glycol represented by the above formula (9), from the viewpoint of compatibility with the refrigerant, at least one of R ^α and R ^γ is preferably an alkyl group, more preferably having 1 to 4 carbon atoms. An alkyl group, more preferably a methyl group.

From the viewpoint of thermal and chemical stability, both R ^α and R ^γ are preferably alkyl groups, more preferably alkyl groups having 1 to 4 carbon atoms, and still more preferably methyl groups.

From the viewpoint of ease of production and cost, one of R ^α and R ^γ is preferably an alkyl group, more preferably an alkyl group having 1 to 4 carbon atoms, still more preferably a methyl group, and the other is a hydrogen atom. is there. From the viewpoints of lubricity and sludge solubility, both R ^α and R ^γ are preferably hydrogen atoms.

R ^β in the above formula (9) represents an alkylene group having 2 to 4 carbon atoms. Examples of such an alkylene group include an ethylene group, a propylene group, and a butylene group. Examples of the oxyalkylene group of the repeating unit represented by OR ^β include an oxyethylene group, an oxypropylene group, and an oxybutylene group. Oxyalkylene group represented by (OR ^β) _f may consist of one oxyalkylene group, or may be composed of two or more oxyalkylene groups.

Among the polyalkylene glycols represented by the above formula (9), a copolymer containing an oxyethylene group (EO) and an oxypropylene group (PO) is used from the viewpoint of compatibility with a refrigerant and viscosity-temperature characteristics. Preferably used. In this case, from the viewpoints of seizure load and viscosity-temperature characteristics, the ratio of oxyethylene groups to the total of oxyethylene groups and oxypropylene groups (EO / (PO + EO)) is preferably 0.1 to 0.8, More preferably, it is 0.3 to 0.6. From the viewpoint of hygroscopicity and heat / oxidation stability, EO / (PO + EO) is preferably 0 to 0.5, more preferably 0 to 0.2, and even more preferably 0 (ie, propylene oxide homopolymer). .

F in the above formula (9) represents the number of repetitions (polymerization degree) of the oxyalkylene group OR ^β and is an integer of 1 to 80. g is an integer of 1 to 8. For example, when R ^α is an alkyl group or an acyl group, g is 1. When R ^α is a residue of a compound having 2 to 8 hydroxyl groups, g is the number of hydroxyl groups that the compound has.

The average value of the product of f and g (f × g) is not particularly limited, but is preferably 6 to 80 from the viewpoint of satisfying the required performance as a refrigerating machine oil in a well-balanced manner.

The weight average molecular weight of the polyalkylene glycol represented by the formula (9) is preferably 500 or more, more preferably 600 or more, preferably 3000 or less, more preferably 2000 or less, and still more preferably 1500 or less. . F and g in the formula (9) are preferably numbers such that the weight average molecular weight of the polyalkylene glycol satisfies the above conditions. When the weight average molecular weight of the polyalkylene glycol is 500 or more, the lubricity in the presence of a refrigerant is excellent. When the weight average molecular weight is 3000 or less, the composition range showing compatibility with the refrigerant under a low temperature condition is widened, and poor lubrication of the refrigerant compressor and inhibition of heat exchange in the evaporator can be suppressed.

The number average molecular weight of the polyalkylene glycol represented by the formula (9) is preferably 500 or more, more preferably 600 or more, preferably 3000 or less, more preferably 2000 or less, and further preferably 1500 or less. . F and g in the formula (9) are preferably numbers such that the number average molecular weight of the polyalkylene glycol satisfies the above conditions. When the number average molecular weight of the polyalkylene glycol is 500 or more, the lubricity in the presence of a refrigerant is excellent. When the number average molecular weight is 3000 or less, the composition range showing compatibility with the refrigerant under a low temperature condition is widened, and poor lubrication of the refrigerant compressor and inhibition of heat exchange in the evaporator can be suppressed.

The weight average molecular weight and the number average molecular weight of the polyalkylene glycol mean the weight average molecular weight and the number average molecular weight (in terms of polypropylene glycol (standard sample)) obtained by GPC analysis, respectively. A weight average molecular weight and a number average molecular weight can be measured as follows, for example.

Prepare a solution using chloroform as a solvent and diluting to a polyalkylene glycol concentration of 1% by mass. The solution is analyzed using a GPC device (Waters Alliance 2695). The analysis is performed using a refractive index detector using a column having a solvent flow rate of 1 ml / min and an analyzable molecular weight of 100 to 10,000. The relationship between the column retention time and the molecular weight is determined using a polypropylene glycol standard with a clear molecular weight, a calibration curve is prepared separately, and the molecular weight of the sample is determined from the obtained retention time.

The hydroxyl value of the polyalkylene glycol is preferably 100 mgKOH / g or less, more preferably 50 mgKOH / g or less, still more preferably 30 mgKOH / g or less, and particularly preferably 10 mgKOH / g or less.

Polyalkylene glycol can be synthesized using a known method ("alkylene oxide polymer", Mitsuta Shibata et al., Kaibundo, issued on November 20, 1990). For example, an alcohol ^{^(R} α OH; R α is the formula (9) R ^alpha same definition are expressed in) by addition polymerization of more than one predetermined alkylene oxide to further terminal hydroxyl groups etherified or ester As a result, a polyalkylene glycol represented by the above formula (9) is obtained. When two or more alkylene oxides are used in the above production process, the resulting polyalkylene glycol may be either a random copolymer or a block copolymer, but tends to be more excellent in oxidation stability and lubricity. In view of the above, a block copolymer is preferable, and a random copolymer is preferable from the viewpoint of excellent low-temperature fluidity.

The kinematic viscosity at 100 ° C. of the polyalkylene glycol is preferably 5 mm ² / s or more, more preferably 6 mm ² / s or more, still more preferably 7 mm ² / s or more, particularly preferably 8 mm ² / s or more, and most preferably 10 mm. and the ² / s or more, and preferably 20 mm ² / s or less, more preferably 18 mm ² / s or less, even more preferably not more than 16 mm ² / s, particularly preferably 15 mm ² / s or less, and most preferably 15 mm ² / s or less. When the kinematic viscosity at 100 ° C. is 5 mm ² / s or more, the lubricity in the presence of a refrigerant is excellent. When the kinematic viscosity at 100 ° C. is 20 mm ² / s or less, the composition range showing compatibility with the refrigerant is widened, and poor lubrication of the refrigerant compressor and inhibition of heat exchange in the evaporator can be suppressed. The kinematic viscosity at 40 ° C. of the polyalkylene glycol is preferably 10 mm ² / s or more, more preferably 20 mm ² / s or more, and preferably 200 mm ² / s or less, more preferably 150 mm ² / s or less. . When the kinematic viscosity at 40 ° C. is 10 mm ² / s or more, lubricity and the sealing property of the compressor can be secured, and when it exceeds 200 mm ² / s, the composition range showing compatibility with the refrigerant under a low temperature condition is wide. Therefore, it is possible to suppress poor lubrication of the refrigerant compressor and inhibition of heat exchange in the evaporator.

The pour point of polyalkylene glycol is preferably −10 ° C. or lower, more preferably −20 ° C. or lower, and preferably −50 ° C. or higher. If the pour point is −10 ° C. or lower, the refrigerating machine oil can be prevented from solidifying in the refrigerant circulation system at low temperatures.

In the production process of polyalkylene glycol represented by the above formula (9), an alkylene oxide such as propylene oxide may cause a side reaction to form an unsaturated group such as an aryl group in the molecule. When an unsaturated group is formed in the polyalkylene glycol molecule, the thermal stability of the polyalkylene glycol itself is reduced, a polymer is produced and sludge is produced, or the antioxidant property (antioxidant property) is lowered. Therefore, a phenomenon such as generation of peroxide is likely to occur. In particular, when a peroxide is generated, it decomposes to generate a compound having a carbonyl group, and the compound having a carbonyl group generates sludge, which easily causes capillary clogging.

Therefore, as the polyalkylene glycol, a polyalkylene glycol having a low degree of unsaturation derived from an unsaturated group or the like is preferably used. The degree of unsaturation of the polyalkylene glycol is preferably 0.04 meq / g or less, more preferably 0.03 meq / g or less, still more preferably 0.02 meq / g or less. The peroxide value is preferably 10.0 meq / kg or less, more preferably 5.0 meq / kg or less, and still more preferably 1.0 meq / kg. The carbonyl value is preferably 100 ppm by weight or less, more preferably 50 ppm by weight or less, and still more preferably 20 ppm by weight or less.

In order to obtain a polyalkylene glycol having a low degree of unsaturation, peroxide value, and carbonyl value, the reaction temperature when reacting propylene oxide is preferably 120 ° C. or less, more preferably 110 ° C. or less. If an alkaline catalyst is used in the production, the use of an inorganic adsorbent such as activated carbon, activated clay, bentonite, dolomite, aluminosilicate, etc. to remove this may reduce the degree of unsaturation. it can. When the polyalkylene glycol is produced or used, contact with oxygen is avoided as much as possible, and an increase in the peroxide value or carbonyl value can also be prevented by adding an antioxidant.

The polyalkylene glycol needs to have a carbon / oxygen molar ratio within a predetermined range. By selecting and adjusting the type and mixing ratio of raw material monomers, a polymer having the molar ratio within the above range can be produced. can do.

The base oil may further contain, for example, a hydrocarbon oil such as mineral oil, olefin polymer, naphthalene compound, and alkylbenzene in addition to the oxygen-containing oil. The content of the oxygen-containing oil is preferably 5% by mass or more, more preferably 30% by mass or more, and still more preferably 95% by mass or more, based on the total amount of the base oil.

The refrigerating machine oil may further contain various additives as necessary. Such additives include acid scavengers, antioxidants, extreme pressure agents, oiliness agents, antifoaming agents, metal deactivators, antiwear agents, viscosity index improvers, pour point depressants, cleaning dispersants, frictions. Examples thereof include a regulator and a rust inhibitor. The content of the additive is preferably 5% by mass or less, more preferably 2% by mass or less, based on the total amount of refrigerating machine oil.

The refrigerating machine oil preferably further contains an acid scavenger from the viewpoint of further improving thermal and chemical stability among the above additives. Examples of the acid scavenger include epoxy compounds and carbodiimide compounds.

The epoxy compound is not particularly limited, and examples thereof include glycidyl ether type epoxy compounds, glycidyl ester type epoxy compounds, oxirane compounds, alkyl oxirane compounds, alicyclic epoxy compounds, epoxidized fatty acid monoesters, and epoxidized vegetable oils. These epoxy compounds can be used individually by 1 type or in combination of 2 or more types.

Examples of glycidyl ether type epoxy compounds include n-butylphenyl glycidyl ether, i-butylphenyl glycidyl ether, sec-butylphenyl glycidyl ether, tert-butylphenyl glycidyl ether, pentylphenyl glycidyl ether, hexylphenyl glycidyl ether, heptylphenyl glycidyl ether Octylphenyl glycidyl ether, nonylphenyl glycidyl ether, decylphenyl glycidyl ether, decyl glycidyl ether, undecyl glycidyl ether, dodecyl glycidyl ether, tridecyl glycidyl ether, tetradecyl glycidyl ether, 2-ethylhexyl glycidyl ether, neopentyl glycol diglycidyl Ether, trimethylolpropa Triglycidyl ether, pentaerythritol tetraglycidyl ether, 1,6-hexanediol diglycidyl ether, sorbitol polyglycidyl ether, polyalkyleneglycol monoglycidyl ether, and polyalkylene glycol diglycidyl ether.

Examples of the glycidyl ester type epoxy compound include glycidyl benzoate, glycidyl neodecanoate, glycidyl-2,2-dimethyloctanoate, glycidyl acrylate, and glycidyl methacrylate.

An alicyclic epoxy compound is a compound represented by the following formula (10), having a partial structure in which carbon atoms constituting an epoxy group directly constitute an alicyclic ring.

Examples of the alicyclic epoxy compounds include 1,2-epoxycyclohexane, 1,2-epoxycyclopentane, 3 ′, 4′-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, bis (3,4-epoxycyclohexyl). Methyl) adipate, exo-2,3-epoxynorbornane, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 2- (7-oxabicyclo [4.1.0] hept-3-yl)- Spiro (1,3-dioxane-5,3 ′-[7] oxabicyclo [4.1.0] heptane, 4- (1′-methylepoxyethyl) -1,2-epoxy-2-methylcyclohexane, 4 -Epoxyethyl-1,2-epoxycyclohexane.

Examples of allyloxirane compounds include styrene oxide and alkyl styrene oxide.

Examples of the alkyloxirane compounds include 1,2-epoxybutane, 1,2-epoxypentane, 1,2-epoxyhexane, 1,2-epoxyheptane, 1,2-epoxyoctane, 1,2-epoxynonane, 1, 2-epoxydecane, 1,2-epoxyundecane, 1,2-epoxydodecane, 1,2-epoxytridecane, 1,2-epoxytetradecane, 1,2-epoxypentadecane, 1,2-epoxyhexadecane, 1, Examples include 2-epoxyheptadecane, 1,2-epoxyoctadecane, 1,2-epoxynonadecane, and 1,2-epoxyicosane.

Examples of the epoxidized fatty acid monoester include esters of an epoxidized fatty acid having 12 to 20 carbon atoms and an alcohol having 1 to 8 carbon atoms, phenol, or alkylphenol. As the epoxidized fatty acid monoester, butyl, hexyl, benzyl, cyclohexyl, methoxyethyl, octyl, phenyl and butylphenyl esters of epoxy stearate are preferably used.

Examples of the epoxidized vegetable oil include epoxy compounds of vegetable oils such as soybean oil, linseed oil and cottonseed oil.

The carbodiimide compound is not particularly limited, and for example, dialkylcarbodiimide, diphenylcarbodiimide, and bis (alkylphenyl) carbodiimide can be used. Examples of the dialkyl carbodiimide include diisopropyl carbodiimide and dicyclohexyl carbodiimide. Examples of bis (alkylphenyl) carbodiimide include ditolylcarbodiimide, bis (isopropylphenyl) carbodiimide, bis (diisopropylphenyl) carbodiimide, bis (triisopropylphenyl) carbodiimide, bis (butylphenyl) carbodiimide, bis (dibutylphenyl) carbodiimide, bis (Nonylphenyl) carbodiimide and the like can be mentioned.

The refrigerating machine oil preferably further contains an antiwear agent among the above-mentioned additives. Suitable antiwear agents include, for example, phosphate esters, thiophosphate esters, sulfide compounds, and zinc dialkyldithiophosphates. Among the phosphate esters, triphenyl phosphate (TPP) and tricresyl phosphate (TCP) are preferably used. Among the thiophosphates, triphenyl phosphorothioate (TPPT) is preferably used. Although there are various types of sulfide compounds, monosulfide compounds are preferably used from the viewpoint of ensuring the stability of refrigerating machine oil and suppressing the deterioration of copper that is frequently used in refrigeration equipment.

The refrigerating machine oil preferably further contains an antioxidant among the above-mentioned additives. Antioxidants include di-tert. Examples thereof include phenol compounds such as butyl-p-cresol and amine compounds such as alkyldiphenylamine. In particular, the refrigerating machine oil contains a phenolic compound as an antioxidant, preferably 0.02% by mass or more and 0.5% by mass or less based on the total amount of the refrigerating machine oil.

The refrigerating machine oil preferably further contains a friction modifier, an extreme pressure agent, a rust preventive agent, a metal deactivator, or an antifoaming agent among the above-mentioned additives. Examples of the friction modifier include aliphatic amines, aliphatic amides, aliphatic imides, alcohols, esters, phosphate ester amine salts, phosphite ester amine salts, and the like. Examples of extreme pressure agents include sulfurized olefins and sulfurized fats and oils. Examples of the rust preventive agent include esters or partial esters of alkenyl succinic acid. Examples of the metal deactivator include benzotriazole and benzotriazole derivatives. Examples of antifoaming agents include silicone compounds and polyester compounds.

The content of the base oil in the refrigerating machine oil is preferably 80 based on the total quantity of refrigerating machine oil in order to be excellent in characteristics required for the refrigerating machine oil such as lubricity, compatibility, thermal / chemical stability, and electrical insulation. It is at least 90% by mass, more preferably at least 90% by mass, even more preferably at least 95% by mass.

The kinematic viscosity at 40 ° C. of the refrigerating machine oil is preferably 3 mm ² / s or more, more preferably 4 mm ² / s or more, still more preferably 5 mm ² / s or more, and preferably 1000 mm ² / s or less. More preferably, it is 500 mm < ² > / s or less, More preferably, it may be 400 mm < ² > / s or less. The kinematic viscosity at 100 ° C. of the refrigerating machine oil is preferably 1 mm ² / s or more, more preferably 2 mm ² / s or more, and preferably 100 mm ² / s or less, more preferably 50 mm ² / s or less. It may be.

The volume resistivity of the refrigerating machine oil is not particularly limited, but is preferably 1.0 × 10 ⁹ Ω · m or more, more preferably 1.0 × 10 ¹⁰ Ω · m or more, and further preferably 1.0 × 10 ¹¹ Ω. -It may be m or more. In particular, when it is used for a hermetic refrigerator, high electrical insulation tends to be required. The volume resistivity in this invention means the value in 25 degreeC measured based on JISC2101: 1999 "electrical insulation oil test method".

The water content of the refrigerating machine oil is not particularly limited, but may be preferably 200 ppm or less, more preferably 100 ppm or less, and most preferably 50 ppm or less, based on the total amount of refrigerating machine oil. In particular, when it is used for a hermetic type refrigerator, the moisture content is required to be small from the viewpoint of the influence on the thermal / chemical stability and electrical insulation of the refrigerator oil.

The acid value of the refrigerating machine oil is not particularly limited, but is preferable in order to prevent corrosion of the metal used in the refrigerating machine or piping and to prevent decomposition of the ester when the refrigerating machine oil contains an ester. May be 1.0 mg KOH / g or less, more preferably 0.1 mg KOH / g or less. The acid value in the present invention means an acid value measured according to JIS K2501: 2003 “Petroleum products and lubricants—neutralization number test method”.

The ash content of the refrigerating machine oil is not particularly limited, but may be preferably 100 ppm or less, and more preferably 50 ppm or less in order to increase the thermal and chemical stability of the refrigerating machine oil and suppress the generation of sludge and the like. The ash content in the present invention means an ash value measured according to JIS K2272: 1998 “Crude oil and petroleum products—Ash and sulfate ash test methods”.

The pour point of the refrigerating machine oil is preferably −10 ° C. or lower, more preferably −20 ° C. or lower, and further preferably −30 ° C. or lower. The pour point in the present invention means a pour point measured according to JIS K2269.

A composition containing, as a base oil, at least one oxygenated oil having a carbon / oxygen molar ratio of 2.5 to 7.5, and a carbon / oxygen molar ratio of 2.5 to 7.5 A composition containing at least one of the following oxygenated oils as a base oil and further containing the various additives described above is a refrigeration used together with a 1-chloro-2,3,3,3-tetrafluoropropene refrigerant. It is suitably used as a component of machine oil or as a component of a working fluid composition for a refrigerator containing a refrigerator oil and a 1-chloro-2,3,3,3-tetrafluoropropene refrigerant.

A composition containing, as a base oil, at least one oxygenated oil having a carbon / oxygen molar ratio of 2.5 to 7.5, and a carbon / oxygen molar ratio of 2.5 to 7.5 A composition containing at least one of the following oxygenated oils as a base oil and further containing the various additives described above is a refrigeration used together with a 1-chloro-2,3,3,3-tetrafluoropropene refrigerant. It is suitably used for producing a working fluid composition for a refrigerator containing machine oil or refrigerator oil and 1-chloro-2,3,3,3-tetrafluoropropene refrigerant.

The refrigerating machine oil according to this embodiment is used together with a 1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd) refrigerant, and in particular, cis-1-chloro-2,3,3,3-tetra. It is preferably used together with a fluoropropene (HCFO-1224yd (Z)) refrigerant. The working fluid composition for a refrigerator according to this embodiment contains 1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd) refrigerant, and preferably cis-1-chloro-2,3. , 3,3-tetrafluoropropene (HCFO-1224yd (Z)) refrigerant.

1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd) refrigerant is cis-1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd (Z)), trans It may be any of -1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd (E)) and a mixture thereof. The 1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd) refrigerant is preferably cis-1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd (Z)). Is contained as a main component. Ratio of cis-1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd (Z)) to 1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd) refrigerant Is preferably 50 mol% or more, more preferably 70 mol% or more, still more preferably 90 mol% or more, particularly preferably 95 mol% or more, and 100 mol% (cis-1-chloro-2,3,3). , 3-tetrafluoropropene (HCFO-1224yd (Z)) alone).

The refrigerant used with the refrigerating machine oil according to the present embodiment and the refrigerant contained in the working fluid composition for the refrigerating machine according to the present embodiment are 1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd). In addition, a known refrigerant such as a saturated fluorinated hydrocarbon refrigerant or an unsaturated fluorinated hydrocarbon refrigerant may be further contained. In this case, the content of 1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd) is preferably 90% on the basis of the total amount of refrigerant from the viewpoint of the stability of the refrigerating machine oil in the refrigerant atmosphere. It is not more than mass%, more preferably not more than 60 mass%, still more preferably not more than 50 mass%, particularly preferably not more than 40 mass%, most preferably not more than 20 mass%. From the viewpoint of reducing GWP, the content of 1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd) is preferably 20% by mass or more, more preferably 40% by mass, based on the total amount of refrigerant. More preferably, it is 50% by mass or more, particularly preferably 60% by mass or more, and most preferably 90% by mass or more.

Saturated fluorinated hydrocarbon refrigerants include difluoromethane (HFC-32), pentafluoroethane (HFC-125), 1,1,2,2-tetrafluoroethane (HFC-134), 1,1,1,2, Tetrafluoroethane (HFC-134a), 1,1-difluoroethane (HFC-152a), fluoroethane (HFC-161), 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) ), 1,1,1,2,3,3-hexafluoropropane (HFC-236ea), 1,1,1,3,3,3-hexafluoropropane (HFC-236fa), 1,1,1, One selected from 3,3-pentafluoropropane (HFC-245fa) and 1,1,1,3,3-pentafluorobutane (HFC-365mfc) A mixture of two or more can be exemplified. Among these, difluoromethane (HFC-32) and 1,1,1,2-tetrafluoroethane (HFC-134a) are preferably used from the viewpoint of the stability of refrigerating machine oil in a refrigerant atmosphere and the reduction of GWP.

Examples of the unsaturated fluorinated hydrocarbon refrigerant include 1,2,3,3,3-pentafluoropropene (HFO-1225ye), 1,3,3,3-tetrafluoropropene (HFO-1234ze), 2,3, 3,3-tetrafluoropropene (HFO-1234yf), 1,2,3,3-tetrafluoropropene (HFO-1234ye), 3,3,3-trifluoropropene (HFO-1243zf), cis-1-chloro One or a mixture of two or more selected from −3,3,3-trifluoropropene (1233zd (Z)) and trans-1-chloro-3,3,3-trifluoropropene (1233zd (E)) Illustrated. Among these, 2,3,3,3-tetrafluoropropene (HFO-1234yf) is preferably used from the viewpoint of the stability of refrigerating machine oil in a refrigerant atmosphere and the reduction of GWP.

The content of the refrigerating machine oil in the working fluid composition for a refrigerating machine is not particularly limited, but is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and preferably 100 parts by mass of the refrigerant. May be 500 parts by mass or less, more preferably 400 parts by mass or less.

The working fluid composition for a refrigerator according to the present embodiment is preferably used for a room air conditioner having a reciprocating or rotating hermetic compressor, a refrigerator, or an open or hermetic car air conditioner. The working fluid composition for refrigerating machine and the refrigerating machine oil according to the present embodiment are preferably used for a dehumidifier, a water heater, a freezer, a freezer / refrigerated warehouse, a vending machine, a showcase, a cooling device for a chemical plant, and the like. The working fluid composition for refrigerating machine and the refrigerating machine oil according to this embodiment are also preferably used for those having a centrifugal compressor.

Hereinafter, the present invention will be described more specifically by way of examples. However, the present invention is not limited to the following examples.

As base oils 1 to 9, polyol esters of fatty acids and polyhydric alcohols having the compositions shown in Tables 1 and 2 were prepared. Abbreviations in the table represent the following compounds.
iC4: 2-methylpropanoic acid nC5: n-pentanoic acid iC8: 2-ethylhexanoic acid iC9: 3,5,5-trimethylhexanoic acid nC10: n-decanoic acid iC18: 2-ethylhexadecanoic acid nC22: docosanoic acid PET: Pentaerythritol DiPET: Dipentaerythritol

The following base oils were used as the base oils 10 to 12.
Base oil 10: Complex ester (Ester of adipic acid, butanediol, neopentyl glycol, and isononanol, carbon / oxygen molar ratio: 5.0)
Base oil 11: polyalkylene glycol (methyl etherified product of both ends of polypropylene glycol, weight average molecular weight: 1,100, carbon / oxygen molar ratio: 2.9)
Base oil 12: polyvinyl ether (copolymer of ethyl vinyl ether and isobutyl vinyl ether, ethyl vinyl ether / isobutyl vinyl ether = 7/1 (molar ratio), weight average molecular weight: 910, carbon / oxygen molar ratio: 4.3)

Test oils 1 to 24 having the compositions shown in Tables 3 to 6 were prepared using the base oils 1 to 12 and the additives 1 to 4 shown below.
Additive 1: Glycidyl neodecanoate additive 2: 2-ethylhexyl glycidyl ether additive 3: tricresyl phosphate additive 4: 2,6-di-tert. -Butyl-p-cresol

The stability test shown below was performed for each sample oil. The results are shown in Tables 3-6.

(Stability test)
The stability test was performed according to JIS K2211: 2009 (autoclave test). Specifically, 80 g of test oil whose water content was adjusted to 100 ppm was weighed into an autoclave, and the catalyst (iron, copper, and aluminum wires, each having an outer diameter of 1.6 mm × length of 50 mm), cis After enclosing 20 g of 1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd (Z)) refrigerant, it was heated to 140 ° C. and the acid value of the test oil after 160 hours (JIS C2101 : 1999).

Further, the following refrigerant compatibility tests were conducted on the test oils 1 to 12, and it was confirmed that any of the test oils was compatible with the refrigerant.

(Refrigerant compatibility test)
In accordance with JIS K2211: 2009 “Refrigerating machine oil” “Compatibility test method with refrigerant”, cis-1-chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd (Z)) refrigerant 10 g 10 g of the test oil was blended, and it was observed whether the refrigerant and the refrigerating machine oil were mutually dissolved at 0 ° C.

Claims

Containing at least one oxygen-containing oil having a carbon / oxygen molar ratio of 2.5 to 7.5 as a base oil;
Refrigerating machine oil used with 1-chloro-2,3,3,3-tetrafluoropropene refrigerant.
The refrigerating machine oil according to claim 1, wherein the oxygen-containing oil contains an ester of a fatty acid and a polyhydric alcohol in which the ratio of the fatty acid having 4 to 20 carbon atoms is 20 to 100 mol%.
Acid scavengers, antioxidants, extreme pressure agents, oiliness agents, antifoaming agents, metal deactivators, antiwear agents, viscosity index improvers, pour point depressants, cleaning dispersants, friction modifiers and rust inhibitors The refrigerating machine oil according to claim 1 or 2, further comprising at least one additive selected from the group consisting of:
A composition containing at least one oxygenated oil having a carbon / oxygen molar ratio of 2.5 or more and 7.5 or less as a base oil, together with a 1-chloro-2,3,3,3-tetrafluoropropene refrigerant Application to refrigeration oil used.
A composition containing at least one oxygenated oil having a carbon / oxygen molar ratio of 2.5 or more and 7.5 or less as a base oil, together with a 1-chloro-2,3,3,3-tetrafluoropropene refrigerant Application for the production of used refrigeration oil.